CARG, CARGF, CARGL - reference manual online

Calculate the complex argument.

Chapter

2015-04-19

CARG(3) Linux Programmer's Manual CARG(3)NAME
carg, cargf, cargl - calculate the complex argument
SYNOPSIS
#include <complex.h>
double carg(double complex z);
float cargf(float complex z);
long double cargl(long double complex z);
Link with -lm.
DESCRIPTION
These functions calculate the complex argument (also called phase angle) of z, with a
branch cut along the negative real axis.
A complex number can be described by two real coordinates. One may use rectangular coor‐
dinates and gets
z = x + I * y
where x = creal(z) and y = cimag(z).
Or one may use polar coordinates and gets
z = r * cexp(I * a)
where r = cabs(z) is the "radius", the "modulus", the absolute value of z, and a = carg(z)
is the "phase angle", the argument of z.
One has:
tan(carg(z)) = cimag(z) / creal(z)
RETURN VALUE
The return value is the range of [-pi,pi].
VERSIONS
These functions first appeared in glibc in version 2.1.
ATTRIBUTES
For an explanation of the terms used in this section, see attributes(7).
┌─────────────────────────┬───────────────┬─────────┐
│Interface │ Attribute │ Value │
├─────────────────────────┼───────────────┼─────────┤
│carg(), cargf(), cargl() │ Thread safety │ MT-Safe │
└─────────────────────────┴───────────────┴─────────┘
CONFORMING TO
C99, POSIX.1-2001, POSIX.1-2008.
SEE ALSOcabs(3), complex(7)COLOPHON
This page is part of release 4.04 of the Linux man-pages project. A description of the
project, information about reporting bugs, and the latest version of this page, can be
found at http://www.kernel.org/doc/man-pages/. 2015-04-19 CARG(3)